This section provides background information related to the present disclosure which is not necessarily prior art.
Total shoulder arthroplasty is one of several types of shoulder replacement surgeries. In total shoulder arthroplasty, a portion of a patient's humerus is replaced with implantable components. These components may include a humeral fixation component and a humeral implant. Generally, the humeral fixation component is fixed to the humerus and the humeral implant is coupled to the humeral fixation component. The humeral implant replaces the head of the humerus and thus contacts the patient's glenoid. Accordingly, the surgically created shoulder is anatomically correct, where the “ball” of the shoulder joint is on the humerus side of the shoulder joint. In some surgeries, the glenoid may also be resurfaced with a glenoid resurfacing component that is positioned between the glenoid and the humeral implant.
Because anatomy varies among patients, a surgeon must choose a humeral implant that fits the patient undergoing surgery. To determine proper fit, a humeral trial is used. Before the humeral implant is installed, the surgeon positions the humeral trial on the humeral fixation component. An adapter assembly may be used to couple the humeral trial to the humeral fixation component where a threaded fastener attaches the humeral trial to the adapter assembly. An apical opening is provided in the humeral trial to receive the threaded fastener and to provide access to the head of the threaded fastener. Once the humeral trial is installed on the adapter assembly and is positioned on the humeral fixation component, the surgeon trials the surgically created shoulder joint by moving the humerus through a range of motion. Such trialing allows the surgeon evaluate the fit and function of the humeral trial. If trialing is unsatisfactory, the surgeon must remove the humeral trial from the humeral fixation component and repeat the process with another humeral trial that has a different size and/or shape. This process continues until a satisfactory humeral trial is found.
Once a satisfactory humeral trial is found, the surgeon removes the humeral trial from the humeral fixation component and reads the position of the humeral trial, which is measured relative to the adapter assembly. The surgeon then selects a humeral implant that matches the size and shape of the humeral trial that is selected during the trialing and replicates the position of the humeral trial relative to the adapter assembly when constructing the humeral implant. The humeral implant is then installed on the humeral fixation component and is positioned in contact with either the glenoid or the glenoid resurfacing component to complete the assembly of the surgically created shoulder joint.
While known implants for total shoulder arthroplasty and related implantation methods may have proven to be generally effective, a continuous need for improvement over the pertinent art remains.